NEW YORK — Jay Ruiz’s cellphone rang about 3:30 a.m. on a stifling Saturday.

It was a woman. As usual, she wanted Ruiz to meet her within the hour and take her home.

Ruiz hauled himself off the sofa where he’d been watching TV, jumped onto his bicycle and pedaled swiftly through Brooklyn to the subway station where the caller was due to arrive. Then, after walking her safely to her door, he rode back home, back to his wife of 19 years, and waited for the next call.